Charging Methods and the Electroscope

Objects can be charged by several methods.

When two suitable materials are rubbed together, electrons may transfer from one material to the other. One object becomes negatively charged and the other becomes positively charged.

A charged object touches another conductor. Electrons are transferred through direct contact. The receiving object usually acquires charge of the **same sign** as the charging object.

A conductor can be charged without direct contact. A nearby charged object causes charge separation inside the conductor. With suitable grounding and removal steps, the conductor can be left with a net charge opposite to the inducing charge.

An **electroscope** is a device used to detect electric charge. A simple electroscope has: metal cap; conducting stem; * two thin metal leaves. When charge reaches the leaves, both acquire similar charge and repel, causing them to separate.

An electroscope can help detect: presence of charge; approximate relative amount of charge; * sometimes charge sign when compared with a known charge.